#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Keypad.h>
#include <Servo.h>                                    //舵机库文件

const int passwordLength = 4;                         //设置密码长度
char correctPassword[5];                              //原始密码
char enteredPassword[passwordLength+1];
int passwordIndex = 0;

Servo myServo;                                        //初始化舵机

int buzzer = 12;                                      //蜂鸣器

#define SCREEN_WIDTH 128                              //宽度
#define SCREEN_HEIGHT 64                              //高度
#define OLED_ADDRESS 0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH,SCREEN_HEIGHT,&Wire,-1);
const uint8_t ROWS = 4;                                //行
const uint8_t COLS = 4;                                //列
char Keys[ROWS][COLS]={
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

uint8_t colPins[COLS]={5,4,3,2};                         //列引脚 
uint8_t rowPins[ROWS]={9,8,7,6};                         //行引脚
Keypad keypad = Keypad(makeKeymap(Keys),rowPins,colPins,ROWS,COLS);

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
strcpy(correctPassword,"4567");
myServo.attach(11);
while(!Serial);
if (!display.begin(SSD1306_SWITCHCAPVCC,OLED_ADDRESS)){
  Serial.println(F("SSD1306 allocatino failed"));
  for(;;);
}
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0,0);
display.println("press Button!");
display.display();
}

void loop() {
  // put your main code here, to run repeatedly:
char correctPassword[5];
char key = keypad.getKey();
strcpy(correctPassword,"4567");

if(key != NO_KEY){                              //按下按钮采取行动
  if(key == '*'){                               //按键按下*号
    if(passwordIndex > 0){                      //密码数>0
      passwordIndex--;                          //删除
      enteredPassword[passwordIndex] = '\0';
      display.clearDisplay();
      display.setCursor(0,0);
      display.println("Enter Password");
      display.setCursor(0,30);
      for(int i=0; i<passwordIndex; i++){
        display.print(enteredPassword[i]);
      }
      display.display();
      delay(200);
    }
  } else if(key == '#'){                                   //按键按下#号
    if(passwordIndex == passwordLength){                   //密码数=密码长度
      if(strcmp(enteredPassword,correctPassword) ==0){
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(0,0);
        display.println("Correct Password");               //正确密码
        display.display();
        myServo.write(90);                                 //舵机转动开锁
        delay(2000);
        myServo.write(0);                                  //舵机复位
        passwordIndex = 0;
        memset(enteredPassword, 0,sizeof(enteredPassword));
        display.clearDisplay();
        display.setCursor(0,0);
        display.println("Enter Password");
        display.display();
      } else {
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(0,0);
        display.println("Wrong Password");                  //错误密码
        display.display();

        tone(buzzer,2200);
        delay(100);
        noTone(buzzer);
        delay(200);

        delay(2000);
        passwordIndex = 0;
        memset(enteredPassword,0,sizeof(enteredPassword));
        display.clearDisplay();
        display.setCursor(0,0);
        display.println("Enter Password");
        display.display();
      }
    }
  } else {
    if(passwordIndex < passwordLength){
      enteredPassword[passwordIndex++]=key;
      display.clearDisplay();
      display.setCursor(0,0);
      display.println("Enter Password");
      display.setCursor(0,20);
      for (int i=0; i<passwordIndex; i++){
        display.print(enteredPassword[i]);
      }
      display.display();
      delay(200);
    }
  }
 }
}